The present invention relates to a door especially for motor vehicles. Such doors may comprise two rails extending at an angle relative to each other, for example, in a V-shape or in a Y-configuration. The reinforcing rails extend between the hinging means arranged on one vertical side or frame member of the door and a lock base plate secured to another vertical member of the door frame. Thus, one reinforcing rail extends substantially horizontally from an upper hinge zone to the lock base plate while the other reinforcing rail extends at an angle from a lower hinge zone to the lock base plate. These rails form a central door structure to which interior and exterior door panels may be secured.
German Patent Publication (DE-AS) No. 1,480,089 discloses a door of this type, for example. Such a door has the advantage, among others, that the interior and exterior door components such as covering panels may be made of synthetic material and solely with regard to the covering function without regard to any load carrying. Thus, a substantial weight reduction may be accomplished however at the expense of a reduction in the door strength. Therefore, this prior art type of door is not capable of satisfying without more, the requirement for an optimal reduction in the danger risk to passengers in a car equipped with such doors when these doors are exposed to a lateral impact as a result of an accident.